The present invention relates to an endoscope treatment device which is inserted in a body cavity through a channel in an endoscope inserted in the body cavity and, more particularly, to a syringe device for directly-injecting a drug solution into a diseased portion in the body cavity.
A treatment method is known wherein, when a drug solution is directly injected into a diseased portion in a body cavity, the distal end of the syringe device is inserted in the body cavity through a channel in an endoscope inserted in the body cavity. A syringe device used for this treatment has an outer tube capable of being inserted in the channel of the endoscope, an injection tube inserted in the outer tube which is capable of moving forward/backward, and a cannula attached to the distal end of the injection tube.
It is dangerous to project the distal end of the cannula from the distal end of the outer tube further than is necessary, since the tip of the cannula may injure the body cavity wall. For this reason, according to the conventional treatment method, a metal stop ring is mounted at the distal end of the injection tube to regulate the projecting length of the cannula, and a shoulder portion of the cannula abuts against the stop ring, thereby regulating the projecting length of the cannula, as disclosed in Japanese Utility Model Disclosure (Kokai) No. 57-126201.
With the conventional syringe device described above, however, the stop ring may fall off the injection tube when the shoulder portion of the cannula abuts against the stop ring strongly. It is dangerous if the stop ring falls off in the body cavity. This is because the body cavity wall may be hurt if the stop ring is left there or if the cannula projects from the distal end of the outer tube more than is necessary.
The injection and outer tubes of a conventional endoscope syringe device are formed by cutting an elongated tube member into predetermined lengths. When the tube member is stored or transported, it is rolled up since it is an elongated member. The tube member thus has a tendency to bend. Therefore, if the tube member with the bending tendency is cut and the cannula is mounted on the distal end of the injection tube without any particular attention being paid, the tip of the cannula may stick in or damage the inner surface of the outer tube.
In order to prevent this, a series of preparations must be performed in advance before performing treatment. The tube material must be corrected to be linear, correcting its bending tendency. However, this is uneconomical since it is laborious and costly.